This is my first post in a series that will describe, discuss, and probably debate, new ways to frame a little house, using standard construction materials, as well as others, such as locally milled timbers. There will be some assumptions made, based on information that I will fill in later, as I describe various sub-systems of the overall building system, which I developed over twenty years ago, and have used in part, or whole, on over a hundred buildings, with full code compliance.
There were multiple reasons for the system I developed. By reducing the amount of framing members in the walls, I was able to design walls that were about twice as thick, and had an Rvalue of 120-150% high (2.2-2.5 time as much) for about the same framing cost. I will go into detail on that part of the system, when I discuss my new ideas on exterior walls, in a later thread, as this series progresses through the building.
My intermediate floors use a “beam & decking”system of 2×6 T&G decking, and beams of various sorts, usually on four foot centers. This allows the decking to be both structural floor, and finished ceiling, and in some cases, even the finished floor. That results in a floor, which takes up a total of only 1½” in depth. This allows a 9″ beam depth to give an 8′-0″ ceiling height with only 7′-3″high walls, useing 7ft studs, that cost 20% less per board foot, than standard precuts, or eight footers. When using 2x6s or 2x8s studs, the least expensive length is usually fourteen feet, and that provides two seven footers. This is barely touching the surface of my system, which has hundreds, if not thousands of such, interrelating factors. That was only presented to give a brief, shallow glimpse into what I mean by “system”
The reason that I want to start with interior walls, is that it seems like a fairly mild way to slip into the mind set, of thinking of framing with the clear ‘virgin'”child’s mind,” required for freedom from the assumption that the existing standard approach to wood framing is based on real world parameters of good housing. Much of it, is not.
Okay! let’s get into it. This will relate to LittleHouses, and their unique need to maximize space. I will be going into areas of detail, that I have not used before. I expect to hear good ideas from others. If that were not the case, I would just do this whole thing in my head, like I have developed my whole system so far (with a little feedback from the real world construction of the houses, which was generally confirming, and occasionally led to new ideas).
Some interior walls are load bearing, but most simply separate space, and provide vertical surfaces. In a LittleHouse, say a 12’x16′ (192ft²) just one wall, running across the short way, will take up 2½% (1/40th) of the floor area. An open floor plan, is one solution, but privacy is at just as much of a premium in a LittleHouse, as floor space is. Walls will be needed. So, we can reduce the thickness. In a very small house, sound insulation must be a consideration too, but most walls, need not serve that purpose. A little trick that I have used, to greatly improve sound insulation, may be able to be applied to thin walls too. That is to rip a slot up the studs from as low as a circular saw will reach, to as high as it will reach. This stops the sound from directly transferring from one side to the other. Filling the wall with cellulose will do a good job of reducing any other sound transfer.
There are places where a narrow wall may only need to be two layers of drywall or paneling, glued back to back, with base moldings screwed together, through the wall, and perhaps, also up through the flooring. There are other places where a similar back-to-back layering can be use, like the back of bookcases, that serve as the walls, instead of setting in front of them. T&G wood, can also make a nice, solid rustic wall. The same 2×6 T&G like used for the flooring, can be used as the walls. When framing a closest, which always requires a great length of short walls, and takes up a large area of floor, these approaches can save a lot of space.
Let’s look at a 4′ wide closet, on an interior wall. In a standard, wasteful design, it would take up nearly 14.4ft² including walls, and only gives 3′-11″ of closet pole. First, we can double about 2½’ of the closet pole, (by running an upper and a lower pole) to give us 5′ of short, and 17″ of long storage. That is 64% more closet pole length. Now let’s see what we can do, to reduce the required floor area. First, eliminate the front wall. Bi-fold doors mount to the floor, and above, so they do not need side jambs, at all. There are various easy way to fill in the small area above the doors. After all, it is only 7″ from the top of the door, to the bottom of the beams, and there may be no reason to fill in the areas between the beams, with wall, especially over a closet door. So, with no front wall, except the door, let’s take 4″ out of the depth of the closet. Now let’s make the side walls, just back to back drywall.
So, that just leaves the back wall. Since one layer of drywall, is stiff enough to span studs on 2’centers, we should be able to do fine with two layers, glued together, for a 4′ span across the back. Perhaps, it would be better to make it stronger, by adding an other, third layer to the others, for safety, if needed. If the wall were longer than 4′, I would also put both outer layers, in a horizontal orientation. It might be necessary to screw through to blocks on either side, halfway up, where the upper and lower sheets meet, as a means of temporarily squeezing and clamping the adhesive. I have never done this. I am just making this part up, as I type. Sail??? feedback…
Anyway, the result of this change in wall framing takes a 47″, 14.4ft² closet, and turns it into a 77″, 9.4ft² one. That is 64% more pole in 35% less space, with only a loss of about 1ft² of floor area inside the closet. That is 2½ time as much closet pole, per square foot, of floor area, that it takes up. That kind of efficiency, of detail, is what can make a LittleHouse ‘big’.
Now, I want to get into what I started this post for. That is a new standard interior wall. There have been a lot of changes in the way we cover walls, since the last time we re-evaluated interior wall framing. Many designers, and builders who even have changed over to 24″ centers in their exterior walls, are still using 16″ centers, for their interior walls. With modern ‘glued and screwed’ drywalling techniques, I see no reason for that. The idea of 2×6 24″oc, equating to 2×4, 16″ oc, has no basis in reason. Furthermore, I see little reason for the general rule of setting the studs transversely. What I am considering, is a radical departure. 1) Instead of three plates (bottom, top, and lap) rip one plate, in two, and use half top, and half bottom. 2) Set the studs for 1½” thick walls. 3) Now here is the big leap. Set the studs on 4′ centers, with continuous 2×4 blocking running horizontally, at the line where the upper and lower drywall sheets meet.
Is this less backing for the drywall? The standard way does not even back the seams, which is where most of the cracking, damage, and failure occurs. The 44½”x40¼”unsupported drywall areas, should be more stiff than the 22½”x92″ areas that are common practice on exterior walls, which does not back the seams. After all, the 24″centers, give 16% MORE unsupported area, plus a long span (92″) that is over twice as long, and the unbacked seam, right at the most likely position, to receive a heavy hit. This looks like a more durable wall, to me.
BTW, this represents a 56% reduction in framing materials from the 16″oc standard, and a 44% reduction in both the floor space, and the living space, it occupies. The labor appears to be about the same. Cellulose, or any other insulation, including foams, could be used for sound and thermal insulation.
What do you think?
With the basic box-beam of a glued and screwed wall, could we rip the 2×4 studs down to 1¾,” saving an additional 11% (total 2/3rds) of the framing materials? My big concern, about this, is drywall cracking, due to flexing. Full 2x4s, or whatever is needed, can still be used, at any points where there is a load to carry.